Showing papers in "Geoderma in 1994"

TL;DR: In this article, the authors compared the performance of kriging and cokriging for predicting four soil variables by these methods and two regression-kriging models, and found that the performance was dependent on the soil variable predicted.

TL;DR: In this article, it is suggested that the generalized cross validation calculated for splines may be a more reliable measure of overall prediction error than the variogram dependent predictive error calculated for kriging.

TL;DR: In this article, the authors compared the profiles of total organic carbon (C) and nitrogen (N) and 13C isotope abundance (expressed in δ13C%o units) of two soils, one under native forest and the other one after ten years under pasture of Pennisetum purpureum.

TL;DR: In this paper, the relationship between small (5 m by 5 m) slope segments and soil distribution has been demonstrated to define larger land-form element complexes in till landscapes of southern Saskatchewan, Canada.

TL;DR: In this article, the relationship between splines, kriging and radial basis functions has been investigated and the positive definiteness property of the variogram connections has been shown between them.

TL;DR: The application of probability and statistics to soil has its origins in agronomy in the early part of this century as discussed by the authors, leading to changes of classifying strategy from hierarchical to non-hierarchical and to a new appreciation of the nature of soil variation itself.

TL;DR: In this article, the effects of two organic amendments, urban refuse and peat, on the improvement of soil structure and to analyse correlations between organic carbon content, fungal and bacteria populations and aggregate stability were investigated.

TL;DR: In this article, the authors compare kriging and cokriging with respect to a set of auxiliary variables (autokrigeability) in the case when all variables are available at the same sample locations.

TL;DR: In this paper, a method based on multivariate geostatistics and redundancy analysis for studying spatial asymmetric relationships between two sets of variables is described, which involves fitting a linear model of coregionalization to all experimental variograms, analyzing coregionization matrices which describe relationships between variables at different spatial scales, and cokriging linear combinations of the predictor variables that account for most variance in the set of dependent variables for a given spatial scale.

TL;DR: In this paper, the spatial and temporal variability of soil water storage were studied on a sandy soil in Ponticelli (NA), Italy, where a neutron probe moisture meter was used to measure the water content at intervals of 15 cm along the vertical soil profiles.

TL;DR: In this paper, the authors studied the different forms of inorganic P (Pi) and organic P (Po) as related to mineralogy and landscape position in semi-arid northeastern Brazil.

TL;DR: In this article, the pseudo cross variogram is used to model the spatial distribution of a soil property at any one time as a realization of a separate random process, and a set of equations with close resemblance to a bivariate cokriging system is derived for describing temporal change from destructive sampling.

TL;DR: The paper discusses three aspects, namely theory, applications, and tools, in terms of current understanding and the research topics that should be investigating in the next few years for the study of soil variability.

TL;DR: In this article, the authors analyzed problems in describing field hydraulic properties of a silty loam, based on data from different laboratory methods: (i) a standard pressure plate apparatus and (ii) a constant-head permeameter were used to measure the static retention characteristics and the saturated hydraulic conductivity independently.

TL;DR: In this article, calcitic pendents are observed at all depths beneath coarse clasts and display a succession of five types of laminae with strongly differentiated overall characteristics, each lamina consists of weakly differentiated micro-laminae that are grouped into six morphological facies.

TL;DR: A computational method to predict the sampling error from prior information in the form of variograms is given and is illustrated with a case study.

TL;DR: In this article, a spatial prediction procedure was devised with two steps: interpolation of the retention data followed by fitting the Van Genuchten function to the interpolated values, and the performance of these methods were compared in an area of 92 ha of alluvial soil where soil changes were gradual.

TL;DR: In this article, the authors used principal components analysis (PCA) to generate a hypothesis that the distribution patterns of mangrove vegetation were influenced by variation in soil properties, tested by simple correlations of vegetation components and soil variables, revealed a primary nutrient/salinity factor as explaining species variation on the first principal component, while the second was explained by physical site quality and micronutrients.

TL;DR: In this paper, a study was conducted on the variation of soil and plant properties within a race field of the Krasnodar region (Russia) using factor analysis and multiple linear regression techniques to explore the nature of variate interactions that may significantly affect crop-yield patterns and to classify and map the soil fertility status in the field.

TL;DR: In this article, a monolith of 50 cm × 80 cm was excavated to a depth of 160 cm, hardened with an epoxy resin and cut into six cross sections, and the coarse fragment contents were determined on the cross sections by counting the aerial fractions belonging to the fine earth, fine gravel and gravel classes.

TL;DR: In this article, a simple air permeameter was developed which allows rapid, in situ measurements to be made of the intrinsic permeability of the soil to air (ka). Measurements of ka are highly dependent on the structure of the soils, in particular the size and continuity of macropores, and therefore can be used as an estimate of functional pore space (pore space contributing to the transmission of air and water) in the soil.

TL;DR: In this paper, an analytical expression describing the moisture retention characteristic was tested using multiple regression on 105 horizons in 34 representative soils from Greece, with textures from loamy sand to heavy clay.

TL;DR: In this article, the suitability of sampling schemes for monitoring soil salinity during the first years of irrigation is studied, where an initial sampling consists of 17 rows and 33 columns of observation points 75 m apart, i.e. 561 data points, regularly spaced on 288 ha.

TL;DR: In this paper, a field survey with ground-penetrating radar (GPR) was conducted on the Newberry Limestone Plain at a site with recently formed dolines, and the results indicated that the subsurface features; presence of clay over limestone, location of solution pipes and paleo-dolines are variable.

TL;DR: In this paper, conditional stability constants (K0) of humic-Al complexes were investigated at pH 4.0, 4.5, 5.0 and 6.0.

TL;DR: In this paper, parent material relations in loess-influenced soils of west-central Kentucky were studied to better understand the nature of the loess and its impact on the soils of that area.